This invention relates to liquid quality monitors and in particular to monitors for boiler condensate water of a power station.
A major source of oil in boiler feed water is turbine lubricating oil from sealing glands. On 500 megawatt fossil fired units an oil level of 0.5 parts per million (ppm) is the maximum acceptable. High oil levels incur cost penalties by contamination of condensate polishing plant, feed-heaters and are also suspected of increasing the risk of boiler tube failure.
There are prior art systems in which there is disclosed a basic oil-in-water monitor for use with such boiler condensate water; however, the present invention is particularly concerned with a low oil concentration boiler condensate monitor, e.g. 0 to 2 ppm.